High-speed vacuum sealing cap



pril 19, 1949. F. w. KRUEGER 2,467,979

HIGH SPEED VACUUM SEALING CAP Filed Feb. 14, 1948 ,Umm/Ey Patented Apr. 19, 1949 2,461,919 HIGH-SPEED vaoUUM SEALIG CAP Frank W. Krueger, Saratoga, Calif., assignor to Food Machinery and Chemical Corporation, San Jose, Calif., a corporation of Delaware Application February 14, 1948, Serial No. 8,342

(Cl. 21S-40) Claims.

This invention relates to the container capping art and is particularly useful in vacuum capping.

Where the product in the container during vacuum capping is of alight granular or powdered consistency. such as that of coffeeV or baking powder, the evacuation step must be performed slowly to prevent particles of the product being withdrawn from the container by the escape of air from the body of the product. This not only constitutes a waste but the product gets between the container and the cap and renders the seal imperfect.

It is an object of this invention to provide a vacuum sealing cap which may be used in ordinary vacuum capping operations which will permit the evacuation step to be performed rapidly without withdrawing particles of the product from the container as above noted.

The manner of accomplishing the foregoing object as well as further objects` and advantages will bev made manifest in the following description taken in connection with the accompanying drawings in which:

Fig. 1 is a cross sectional view of a circular cap constituting a preferred embodiment of the invention.

Fig. 2 is a fragmentary sectional view of the open upper Aend of a glass jar filled with a granular product such as coffee and suitable for sealing by the cap show n in Fig. 1.

Fig. 3 is a view similiar to Fig. 2 and illustrates the partial application of the cap shown in Fig. 1 to the jar shown in Fig. 2 which takes place prior to the evacuation step of the vacuum capping process.

Fig. 4 is a view similar to Fig. 3 and illustrates the screwing of the cap embodying the invention linto completely sealing relation with the jar during the maintenance of a vacuum which was imposed while the cap was partially applied as shown in Fig. 3.

Referring specifically to the drawings the in- `vention is there illustrated as embodied in a cap Il) which is a screw cap formed in the ordinary manner of thin sheet metal to provide a disc-like body Il shaped at its periphery to form an annular inverted channel I2 having an inner wall I3 and a bottom wall I4, the outer wall of said channel being formed by an annular securing flange I5 having threads I6 rolled therein and a bead l1 rolled from the lower edge of the ange.

An annular strainer element I8, which preferably comprises a circular band of porous paper, is inserted in the cap I0, this being of such a diameter as to fit into the sealing material recess 2 I9 formed by the channel I2 and to lie snugly y against the inner wall of this channel when so inserted.

After the element I8 has been assembled with the cap I0, a sealing material 20, such as latex, is introduced into the recess I9 so as to constitute an annular seal member which adheres to the Walls of the recess Iland to the element I8 and permanently assembles said element with the cap.

The cap I0 is adapted for being used in vacuum capping a glass jar 25, having an open mouth 25, providing a sealing edge 21 and having a converging inner surface 28. Molded on the exterior `of the jar mouth 26 is a helical thread 29 with which the threads I6 of the cap is adapted to mesh when the cap is rotated as it is applied to the jar 25.

The element I8 is preferably cylindrical in character and ts within the mouth 26 when the cap is partially applied to said mouth as illustrated in Fig. 3. This causes the element I8 to be slightly -constricted to bringthis into snug contact with the surface 28 entirely around the jar mouth 25.

Jar 25 is shown in the drawings as having a quantity of granular material 30, such as coffee, packed therein. When employing cap I0 for capping the jar 25 in a vacuum capping operation, the cap is partially applied to the jar (as shown in Fig. 3) either Ibefore or during the formation of a vacuum chamber surrounding the upper end of the jar 25. With the cap so positioned, the air is evacuated from this chamber, this evacuation also extending to the air contained .in the jar 25 owing to the loose application of the cap to the jar. This evacuation of air from the interior of the jar 25 may be rapidly effected because the porous character of the element I8 adds practically no resistance to the evacuation from the jar, yet this element acts as a filter which prevents granular particles of the product 30 from being carried by the air into the space between the sealing material 20 and the jar sealing surface 21.

Thus the product isall retained within the jar 25 no matter how rapidly the evacuation of air therefrom is effected. The space between the surface 21 and the sealing material 20 is therefore entirely free of product and when the sealing of the jar is effected by screwing the cap I0 thereon (as shown in Fig. 4) a perfect seal of the jar is accomplished.

The claims are:

1. A cap for use in vacuum sealing the mouth of a container, said cap comprising: a disc-like body having an annular peripheral recess surrounded by an annular securing flange; sealing material in said annular recess for engaging said container mouth to form a seal between said cap and said mouth when said cap is advanced into sealing relation with said mouth; and an annular filtering element provided on said cap, said ele ment being adapted Yto t said container mouth when said cap is partially advanced onto said container mouth whereby air sucked from said container will, of necessity, pass through said element thereby retaining within said container any particles of product tending to be entrained in the air thus withdrawn from said container.

2. A cap for use in vacuum sealing the mouth of a container, said cap comprising: a disc-like body having an annular peripheral recess surrounded by an annular securing flange; sealing material in said annular recess for engaging said container mouth to form a seal between said cap and said mouth when said cap is advanced into sealing relation with said mouth; and an annular iltering 'element provided on said cap at the inner edge of said sealing material, said element being adapted to iit said container mouth when said cap is partially advanced onto said container mouth whereby air sucked from said container will, of necessity, pass through said element thereby retaining within said container any particles of product tending to be entrained in the air thus withdrawn from said container.

3. A combination as in claim 1 in which said element is of relatively porous paper.

4. A combination as in claim 2 in which said element extends between said cap and said sealing material and is thereby assembled with said cap.

5. A combination as in claim l in which said annular element is entirely confined within said flange.

FRANK W. KRUEGER.

No references cited. 

